Insulatingly covered dynamoelectric machine

ABSTRACT

Insulation systems as well as winding retaining means for dynamoelectric machines having winding accommodating magnetic cores and methods of making same are described. Ground insulation system may include one or more formed in situ insulation members with portions thereof providing retainer means for constraining windings accommodated by a magnetic core from undesired movement. With tongue shape retainer means, access means may also be provided for facilitating the removal of defective winding turns accommodated on a given core. With formed in situ insulating members, retainer means for terminals and terminal boards may be provided along with winding retainer means, by little effort and expense. Similarly, spacer and other means may be provided. In one exemplification, formed in situ insulation system, coupled with molded housing means for winding turns provide substantially improved isolating insulation system for winding turns.

[ Dec. 18, 1973 Primary ExaminerD. F. Duggan Attorney-Joseph B. Formanet a1.

57 ABSTRACT Insulation systems as well as winding retaining means fordynamoelectric machines having winding accommodating magnetic cores andmethods of making same are described. Ground insulation system ma in- 3clude one or more formed in situ insulation members 310/214 withportions thereof providing retainer means for H02k l/04 constrainingwindings accommodated by a magnetic 310/259, 93, 1, core from undesiredmovement. With tongue shape 3 /2 94; 310/214 retainer means, accessmeans may also be provided for facilitating the removal of defectivewinding turns accommodated on a given core. With formed in situinsulating members, retainer means for terminals and United StatesPatent [1 1 INSULATINGLY COVERED DYNAMOELECTRIC MACHINE Inventor: CarlE. Swain, Fort Wayne, 1nd.

Assignee: General Electric Company, Fort Wayne, lnd.

Filed: Sept. 15, 1971 Appl. No.: 180,757

Field of Search........................

References Cited UNITED STATES PATENTS VJXU "1 .mfle m fl da c .m n wmmm m s eila m. mdm e .yn WSAuSin ne W .l fi n g r. nplOr u ox ml g Mew.1 d m m F n S g aen .B n d .0 6 .1 I t w V-l e 8. V a rwum g P. De .mmD s. S iwn um 6 3 00 5 wl eh n m mm Hm .I S fdm C swa 2 aaODmM m m mmnmhww 1 a t 3 m r. n rrlw o m lnd mmmmm mrseppm XMXMMXX M Ull/l O0 030Hll l 4 033/0 S3 1.3 3 3 u "mm m. .MMT m m m C n n. W m m "P. W D...mm N m a m m R.m m n m nmave h H u d M oe w u T e uo o ea r SRMHTDG G T3505022 A6 6666666 5 9999999 9 /HHHHHHNH 270 43 0 1 11 1 E 0577585 R0589752706 -Q -AF9 5640 07 9 724 632 5 7 3323233 Swain PATENTEB DEC 18I975 SHEET 1 [)F 2 ATTORNEY.

PAIENIEDUEC 18 1975 3.780.323 sum 2 or 2 FIG.3

INVENTOR.

CarL E. Swafm AT TORNEY.

INSULATINGLY COVERED DYNAMOELECTRIC MACHINE CROSS REFERENCE TO RELATEDAPPLICATIONS Church US. Pat. application Ser. No. 99,049 titledLAMINATED STRUCTURE WITH INSULATING MEMBER FORMED IN SITU THEREON ANDMETHOD AND APPARATUS FOR ACHIEVING. SAME and filed Dec. I7, 1970, whichissued as US. Pat. No. 3,709,457 on Jan. 9, I973; Deuter US. Pat.application Ser. No. 180,770 filed on Sept. 15, I97l and titled PRESSUREMOLDED ARTICLES, COM- POSITION, AND METHOD OF MAKING SAME; and Deuterand Shaffer US. Pat. application Ser. No. 180,728 titled APPARATUS ANDMETHOD FOR MAKING A MOLDED "ELECTRICAL STRUCTURE and filed on September15, 1971 are related applications. The disclosures of all three of theabove applications are specifically incorporated herein by reference.

BACKGROUND OF THE INVENTION The present invention relates todynamoelectric machines and, more particularly, to such machinesincluding molded in situ insulation material.

Heretofore, what has come to be known as ground insulation fordynamoelectric machine (e.g., transformer, motor, and generator)magnetic cores have been provided by following one of several differentapproaches. In the case of motor stator cores, for example, separateinsulators for winding accommodating core slots have sometimes beenprovided. Such insulators have been formed from materials such as kraftpaper, cellulose acetate or still other plastic materials.

Another approach has involved an integral insulation as taught forexample in Baciu US. Pat. No. 2,978,371, issued Apr. 4, 1961, which isassigned to the assignee of the present invention. Of course integralinsulation has also been applied by powdered spray and fluidized bedapproaches.

All of the above approaches have been, however, relatively expensive inpractice for both material and labor.

Still other relatively expensive aspects of dynamoelectric machinemanufacture has been related to providing means for holding laminationstogether in stacked relationship and for retaining winding turns in adesired position on a stator core. One technique used heretofore tosolve multiple problems is shown, inter alia, in DeJean US. Pat. No.3,030,528, issued Apr. 17, 1962. This patent discloses, for example, amethod of holding core laminations together during the application ofinsulating and bonding material without use of keys, rivets, welds, orthe like which'tend to increase core losses during machine operation.For example, core laminations are held together by the use of windingretaining pins fitted tightly into winding pin holes through corelaminations. I

Though the use of winding pins to hold core laminations together inconjunction with the use of ground insulation material between theenergizing coils and magnetic core did indeed advance the dynamoelectricmachine art it would nevertheless, of course, be desirable to reduce, ifnot eliminate the material and labor cost due to the use of such pins.Moreover, the expense related to protecting and or holding terminationmeans would also, desirably, be produced.

Church US. Pat. No. 3,709,457; Deuter US. Pat. application Ser. No.180,770 and Deuter et al. U.S. Pat. application Ser. No. 180,728disclose noteworthy and valuable advances in the art, however, and itwould be desirable to provide new and improved dynamoelectric machinesand methods of making the same that overcome the previously statedproblems and also, where desirable, practice the invention of suchChurch, Deuter et al., and Deuter applications.

SUMMARY OF THE INVENTION Accordingly, it is an object of the presentinvention to provide an improved dynamoelectric machine.

A further object of the present invention is to provide a dynamoelectricmachine stator core formed of a stack of magnetic laminations and havingmolded in situ insulation means and a molded interstitial structure forat least some winding turns accommodated on the core.

Another object of the invention is to provide a dynamoelectric machinewith improved insulating retaining means and molded in situ insulation.

Still another object of the invention is to provide a salient poledynamoelectric machine with a molded in situ body of electricalinsulation covering winding accommodating regions of the core and thatalso includes winding and/or termination means retaining means.

A still further object of the present invention is to provide adynamoelectric machine having a body of insulation formed in stiuthereon which includes means for accommodating winding removal and coresalvage operations.

In carrying out the above and other objects in one preferred form, thereis provided a dynamoelectric machine comprising a laminated magneticcore having inner and outer peripheral surfaces and windingaccommodating means, in the form of winding accommodating slots,disposed between such surfaces.

In one exemplification, molded in situ insulating means provide groundinsulation for the winding and may also include retaining means forretaining winding turns and/or terminations in a predetermined positionrelative to the core. In another exemplification, a substantially solidand rigid interstitial mass of particulate material is secured in placeby a substantially solid and rigid matrix to cover at least part of atleast some winding turns. In both exemplifications, winding retainingmeans preferably include tongues projecting from at least one end faceof the core, the tongues being provided with means in the form of slotsfor facilitating winding removal and core salvage operations. Inaddition, retaining means for terminations including terminal receivingreceptacles or receptacles for a termination supporting member areprovided and may be formed from formed in situ insulating material. Apreferred method includes, in one form, molding insulation material insitu on a magnetic core, accommodating winding turns on the core, andmolding a protective covering against at least part of the windingturns.

The subject matter which I regard as my invention is set forth in theappended claims. The invention itself, however, together with furtherobjects and advantages thereof may be better understood by referring tothe following more detailed description taken in conjunction with thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation, with partsin section and parts broken away of a dynamoelectric machine embodyingthe invention in one form;

FIG. 2 is a perspective view of a portion of the dynamoelectric machineof FIG. 1;

FIG. 3 is a plan view with parts removed, of the structure of FIG. 2;

FIG. 4 is a side elevation of the structure of FIG. 3;

FIG. 5 is a perspective view, with parts broken away, of a wound statorcore to illustrate another exemplification of the invention; and

FIG. 6 is a side elevation, with parts in section and parts broken away,of another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in more detail tothe drawings, there is shown in FIG. 1 a dynamoelectric machineillustrated as a motor 10, embodying the invention in one form. Themotor 10 includes a stator core 11 comprised of a stack of magneticlaminations 12, molded in situ insulating means indicated generally bythe numeral 13, a winding 14, cast iron shell 16, steel cover 17, aconventional rotor 18, oil well cover 19, and termination means notshown in FIG. 1.

The motor 10 of course includes other assembled components such asbearing means and a lubrication system, as will be understood by personsskilled in the art.

Turning now to FIGS. 2, 3, and 4, the core 11 includes a magnetic yokesection 21 with an outer peripheral surface 22 and also includesradially inwardly projecting tooth sections 23 for establishing salientpolar regions or poles. The tips of sections 23 in turn define innerperipheral surfaces 24 that collectively define the bore 26 of thestator core. It should be specifically noted at this point that asalient pole stator core has been selected for purposes ofexemplification only and that the invention may also be embodied inother types of apparatus, including distributed wound or nonsalient polemotors and generators or alternators. About each pole defining toothsection is wound a winding coil 27 having a plurality of side turnportions 28 and end turn portions 29 as will be understood. In addition,one or more shading coils 31 are provided for each pole.

Ground insulation, i.e., insulation between the magnetic core andwinding coils is molded in situ on the core as shown at 32. Theinsulation 32 covers at least those portions of each tooth sectionadjacent to which side turn or end turn portions of the winding are tobe disposed. This covering then electrically insulates the energizingcoils from the laminated magnetic core.

Thus, ground insulation is provided for coils accommodated by windingaccommodating regions of the core 11. More specifically, windingsdisposed in the winding accommodating slots 33 are separated byinsulating material from the laminations of core 11.

As may be seen more clearly by reference to FIGS. 2 and 4, the molded insitu insulation or insulating means also includes a plurality ofretaining means. Preferably, this includes termination and windingretaining means.

In a preferred form, the winding retaining means includes a plurality oftongues 34 that project substantially normally from each end face 36, 37of the core 11. There situated, the tongues serve to retain theenergizing coils from undesired movement toward the inner peripheralsurface of the core 11. This arrangement is of particular advantagewhile placing the winding turns on the core 11.

Also as best shown in FIGS. 2 and 4, winding retaining means may bearranged to retain the windings from movement toward the outerperipheral surfaces of the core 11 and, accordingly, cylindrical rims38, 39 are provided to project substantially normally from each core endface 36, 37. The edges of rims 38, 39 are wavy with wave crests and withwave troughs disposed therebetween as illustrated. These rim portionsretain the winding against movement and are of particular advantage whenthe windings are subjected to a flowable blended molding composition ina molding process as described in more detail in Deuter US. Pat.application Ser. No. 180,770 and Deuter et al. US. Pat. application Ser.No. [80,728 and as will be discussed hereinafter in more detail inconjunction with a description of FIG. 6.

Tongues 34 are each seen to be bifurcated by notches 41. Rims 38likewise have notches 42 therein. Each of the illustrated notches isdisposed adjacent the centerline of a winding coil. These notchesfacilitate core salvage by providing improved access of tools to thewinding coils so that damaged windings may be cut and re moved from acore. During salvage operations a wire cutting tool may be insertedthrough the notches into contact with each side of the coilssimultaneously if desired. This would be done, for example, if aconventional test showed that the winding was damaged after or duringplacement on a core.

The retaining means of the preferred embodiment also includestermination retainers in the form of a pair of hollow projections orreceptacles 43 which extend substantially normally from one of the coreends. One or more coil wires 44 having insulation stripped therefrom maybe electrically connected with a terminal 46 to form a terminationmeans, with the terminals then being placed and retained in thereceptacles as best shown in FIG. 2.

Alternatively, the winding termination means may be in the formillustrated by FIG. 5 wherein such means are generally denoted by thereference numeral 47. The means 47 include an electrical interconnectionbetween coil leads 48, 49 and lead wires 51, 52; a barrier 53 ofthermoresponsive material such as General Mills Companys Versamid"material disposed to prevent the inadvertent removal of the terminationmeans 47 from the core 54; and a barrier supporting member 56. Thebarrier supporting member in turn is disposed in receptacle means thatare shown as notches 57, 58 formed in two adjacent tongue shapedretaining member 61, 62 in FIGS. 2, 4 and 5.

I have also provided spaced apart surface areas, designated as areas 66and 67 in FIGS. 2 and 4 and which are illustrated as the ends oflocating spacers or tabs 68, 69 which are formed in situ with theinsulating means. The surface areas 66, 67 are located preselecteddistances from the end face 36 of the core and are of particularadvantage when an insulating covering is to be molded against all orpart of at least the winding as will be described hereinafter.

The molded body of insulation is preferably formed in situ on thelaminated magnetic portions of the stator core by following theteachings of Church US. Pat. No. 3,709,457 so as to not increase theelectrical losses of the core as a result of compressive stressestherein. This may be done by positioning stack under predeterminedcompressive force by clamping means such as pressure pins mounted in thecavity of suitable molding apparatus. An unhardened polyamide resin atelevated temperature may then be introduced under pressure into theclosed mold cavity. A particularly well suited and readily availablenylon material for this purpose is Zytel 101 resin sold by the E. l. duPont de Nemours and Co., Inc. This material is preferably moved into themold at about 580 F. under pressure of about 12,000 psi, again, all astaught in the incorporated by reference Church patent.

With reference now to FIG. 6, I have there shown a portion of stillanother dynamoelectric machine embodying the invention in an even morepreferred form, In the case of the dynamoelectric machine 80, aninsulating covering is provided substantially entirely around the moldedin situ insulating body 81, core 82 and winding 83. Although any one ofanumber of different processes may be used for forming this insulatingcovering, generally denoted by the reference numeral 84, moresatisfactory results have been obtained by utilizing the approachestaught by Deuter et a]. in their US. Pat. application Ser. No. 180,728and by utilizing materials for molding composition as taught in DeuterUS. Pat. application Ser. No. 180,770. When those approaches arefollowed (all of the same being specifically incorporated by referencehereinabove), a dynamoelectric machine structure comprising an assemblyof components results wherein the windings are substantially completelysurrounded by insulating material, the insulating covering separatingthe windings from the environment of the dynamoelectric machine and themolded in situ insulating member separating the windings from thelaminated core. For this exemplification 13 percent glass reinforcednylon insulating material is preferred but not required.

However, all of the advantages that may be obtained by following theteachings of the present invention may just as well be achieved evenwhen an insulating protectice covering is provided for only a part ofsome of the winding turns of the winding 83.

It will be understood that in the formation of the insulating covering84, a stator core such as the core 82 having the insulating member 81and windings 83 positioned thereon is placed in the cavity of a piece ofpressure molding equipment which may be of the injection, transfer, orany other suitable pressure molding type.

When this is done, the locating surfaces 66, 67 may advantageously beutilized as bearing surfaces for the wound and insulated core componentwithin the second mold cavity (the first mold cavity beingthe cavity inwhich the insulating material 81 is molded in situ on the core).Thereafter, a molding composition comprising a blended matrix formingmixture as described in more detail in the above mentioned Deuterapplication and a mass of particulate material such as sand are forced,under pressure, into the mold cavity and into intimate engagement withthe windings 83, exposed portions of the core 82, and the insulatingmember 81. At this time, due to the relatively high pressures,velocities, and viscosity of molding composition being employed, theregaining means such as tongues 34 and rim 38 may be of great benefit inpreventing undesired movement of the windings relative to the statorcore. Moreover, by providing receptacle means in the insulating body,any pressure exerted against the termination means of a core having aninsulating covering formed therearound does not bend or otherwisedisturb a predetermined dimensional relationship between the windingtermination means and the magnetic core within the mold cavity.

Although I have described above and illustrated harein two preferredexemplified dynamoelectric machines and portions thereof embodying theinvention in one form, it will be understood that the invention itselfwill have other applications. Moreover, it should be clear at this timethat the advantages and features of the invention are numerous.

Accordingly, while in accordance with the Patent Statutes I havdescribedwhat at present are considered to be the preferred embodiments of myinvention, it will be obvious to those skilled in the art that numerouschanges and modifications may be made therein without departing from theinvention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. A dynamoelectric machine comprising a magnetic core having aplurality of spaced apart tooth sections and core surfaces defining atleast one winding turn accommodating slot; a body of insulating materialmolded in situ on the magnetic core that establishes an insulatingcovering at least for core surfaces defining the at least one windingturn accommodating slot; a plurality of winding turns having side turnand end turn portions, with at least part of the side turn portions ofat least some of the winding turns positioned in the at least onewinding turn accommodating slot adjacent to said insulating covering,said insulating covering providing electrical insulation between thecore and winding turns adjacent thereto; and winding termination means;said body of insulating material including a winding retaining meansextending axially from an end face of the magnetic core and having afree extremity spaced from the end face, said body of insulatingmaterial defining receptacle means for at least a portion of saidwinding termination mans; a bundle of winding end turns disposedadjacent to the winding retaining means and extending axially from afirst locale in proximity to the core end face toward the free extremityof the winding retaining means; said winding retaining means having atleast one tool admitting passage formed therein that extends axiallyfrom the free extremity of the winding retaining means along the bundleof winding end turns to a location proximate to the first locale, tofacilitate removal of winding turns from the core; said windingtermination means comprising an electrical interconnection between saidat least one winding and an external lead wire; a mass of electricallyinsulating material being disposed as a barrier on the interconnection;and a barrier supporting member being supported by said receptaclemeans.

2. A dynamoelectric machine comprising a magnetic core having aplurality of spaced apart tooth sections and core surfaces defining atleast one winding turn accommodating slot; a body of insulating materialmolded in situ on the magnetic core that establishes an insulatingcovering at least for core surfaces defining the at least one windingturn accommodating slot; a

plurality of winding turns having side turn and end turn portions, withat least part of the side turn portions of at least some of the windingturns positioned in the at least one winding turn accommodating slotadjacent to said insulating covering, said insulating covering providingelectrical insulating between the core and winding turns adjacentthereto; and winding termination means; said body of insulating materialincluding a winding retaining means extending axially from an end faceof the magnetic core and having a free extremity spaced from the endface, said body of insulating material defining receptacle means for atleast a portion of said winding termination means; a bundle of windingend turns disposed adjacent to the winding retaining means and extendingaxially from a first locale in proximity to the core end face toward thefree extremity of the winding retaining means; said winding retainingmeans having at least one tool admitting passage formed therein thatextends axially from the free extremity of the winding retaining meansalong the bundle of winding end turns to a location proximate to thefirst locale, to facilitate removal of winding turns from the core; saidwinding termination means including at least one terminal element and anelectrical interconnection between the at least one winding and the atleast one terminal element; at least a portion of the at least oneterminal element being received in and supported by said receptaclemeans.

1. A dynamoelectric machine comprising a magnetic core having aplurality of spaced apart tooth sections and core surfaces defining atleast one winding turn accommodating slot; a body of insulating materialmolded in situ on the magnetic core that establishes an insulatingcovering at least for core surfaces defining the at least one windingturn accommodating slot; a plurality of winding turns having side turnand end turn portions, with at least part of the side turn portions ofat leaSt some of the winding turns positioned in the at least onewinding turn accommodating slot adjacent to said insulating covering,said insulating covering providing electrical insulation between thecore and winding turns adjacent thereto; and winding termination means;said body of insulating material including a winding retaining meansextending axially from an end face of the magnetic core and having afree extremity spaced from the end face, said body of insulatingmaterial defining receptacle means for at least a portion of saidwinding termination mans; a bundle of winding end turns disposedadjacent to the winding retaining means and extending axially from afirst locale in proximity to the core end face toward the free extremityof the winding retaining means; said winding retaining means having atleast one tool admitting passage formed therein that extends axiallyfrom the free extremity of the winding retaining means along the bundleof winding end turns to a location proximate to the first locale, tofacilitate removal of winding turns from the core; said windingtermination means comprising an electrical interconnection between saidat least one winding and an external lead wire; a mass of electricallyinsulating material being disposed as a barrier on the interconnection;and a barrier supporting member being supported by said receptaclemeans.
 2. A dynamoelectric machine comprising a magnetic core having aplurality of spaced apart tooth sections and core surfaces defining atleast one winding turn accommodating slot; a body of insulating materialmolded in situ on the magnetic core that establishes an insulatingcovering at least for core surfaces defining the at least one windingturn accommodating slot; a plurality of winding turns having side turnand end turn portions, with at least part of the side turn portions ofat least some of the winding turns positioned in the at least onewinding turn accommodating slot adjacent to said insulating covering,said insulating covering providing electrical insulating between thecore and winding turns adjacent thereto; and winding termination means;said body of insulating material including a winding retaining meansextending axially from an end face of the magnetic core and having afree extremity spaced from the end face, said body of insulatingmaterial defining receptacle means for at least a portion of saidwinding termination means; a bundle of winding end turns disposedadjacent to the winding retaining means and extending axially from afirst locale in proximity to the core end face toward the free extremityof the winding retaining means; said winding retaining means having atleast one tool admitting passage formed therein that extends axiallyfrom the free extremity of the winding retaining means along the bundleof winding end turns to a location proximate to the first locale, tofacilitate removal of winding turns from the core; said windingtermination means including at least one terminal element and anelectrical interconnection between the at least one winding and the atleast one terminal element; at least a portion of the at least oneterminal element being received in and supported by said receptaclemeans.